This invention relates to an endotracheal intubation method and an associated instrument assembly for use in performing the method.
During a major surgical operation, a patient is anaesthetized and accordingly requires endotracheal intubation for purposes of providing oxygen to one or both lungs. Generally, unless one of the lungs is being operated on, it is desirable to place the distal end of the endotracheal tube proximally of the junction between the bronchi.
Endotracheal intubation can be difficult even for an experienced anaesthesiologist. The endotracheal tube can be inadvertently placed down the esophagus instead of the windpipe. Moreover, even if the tube is correctly placed at the onset of an operation, it can become dislodged as a consequence of the movements of the patient caused by the operative procedures. Thus, it is important to periodically determine the location of the endotracheal tube during an operation.
The positioning of an endotracheal tube is determined currently by three methods. First, the anaesthesiologist listens to the lungs during a lung oxygenation or pressurization step. The sounds made upon proper endotracheal tube placement are generally different from the sounds made upon an improper placement. Second, the carbon dioxide content of gases expelled via the endotracheal tube is measured. If the tube is improperly placed in the esophagus, there will be no carbon dioxide in the outcoming gases. Third, tissue oxygenation, for example, in the finger, is measured to determine whether the blood is carrying oxygen to the patient's tissues.
None of these methods is universally effective in determining proper endotracheal tube placement.